A U.S. Customs and Border Patrol agent patrols a section of floating fence at sunset that runs through Imperial Sand Dunes Wednesday, July 18, 2018 along the international border with Mexico in Imperial County, Calif. 126-miles of border cuts through the Yuma Sector where thousands of families and unaccompanied children are continuing to cross into Arizona and California even after learning of the government's family separation policy upon apprehension. (AP Photo/Matt York)

A U.S. Customs and Border Patrol agent gathers information on four Guatemalan nationals, including two men and a pair of 12 and 13-year-old boys, Wednesday, July 18, 2018, in Yuma, Ariz. Thousands of families and unaccompanied children are continuing to cross the U.S. border in Arizona and California even after learning of the government's family separation policy upon apprehension. (AP Photo/Matt York)

Four Guatemalan nationals consisting of two men and a pair of 12 and 13-year-old boys, remove their shoe laces and personal itmes after being arrested by a U.S. Customs and Border Patrol agent Wednesday, July 18, 2018 in Yuma, Ariz. Thousands of families and unaccompanied children are continuing to cross the U.S. border in Arizona and California even after learning of the government's family separation policy upon apprehension. (AP Photo/Matt York)

A mother and 5-year-old daughter from Honduras are detained by U.S. Customs and Border Patrol agents Wednesday, July 18, 2018, in San Luis, Ariz. The pair were apprehended by a U.S. Border Patrol agent who spotted them crossing a canal along the border with Mexico. (AP Photo/Matt York)

FILE - In this Friday, July 20, 2018 file photo people walk and fish on the beach and children play soccer on the Mexico side of the the border wall as seen from the Friendship Park in San Diego. A congressional watchdog agency says the Trump administration's plan to erect hundreds of miles of barriers along the border with Mexico fails to adequately consider costs, potentially raising the price and creating delays. The Government Accountability Office said Monday, AUG. 6, 2018, that costs can vary considerably based on the slope and topography, land acquisition costs and other factors. (AP Photo/Richard Vogel,File)

FILE - This Oct. 26, 2017 file photo shows prototypes of border walls in San Diego. A federal appeals court will hear arguments by the state of California that the Trump administration overreached by waiving environmental reviews to speed construction of the presidentÕs prized border wall with Mexico. At issue Tuesday, Aug. 7, 2018, before a three-judge panel in Pasadena, Calif., is a 2005 law that gave the Homeland Security secretary broad authority to waive dozens of laws including the National Environmental Policy Act and Endangered Species Act. (AP Photo/Elliott Spagat, File)

Members of the Center for Biological Diversity and other immigrant advocates protest outside 9th U.S. Circuit Court of Appeals court hearing challenging Trump's border wall Tuesday, Aug. 7, 2018, in Pasadena, Calif. A federal appeals court will hear arguments by the state of California that the Trump administration overreached by waiving environmental reviews to speed construction of the president's prized border wall with Mexico. At issue Tuesday before a three-judge panel in Pasadena, California, is a 2005 law that gave the Homeland Security secretary broad authority to waive dozens of laws including the National Environmental Policy Act and Endangered Species Act. (AP Photo/Ariel Tu)

FILE - In this June 22, 2018, file photo, Commerce Secretary Wilbur Ross, testifies on Capitol Hill in Washington. Democratic lawmakers want Ross to clarify where a citizenship question on the 2020 census originated after newly released documents show he was seeking such a question early in Donald TrumpÕs presidency. (AP Photo/Manuel Balce Ceneta, File)

From left, Customs and Border Protection U.S. Border Patrol Acting Chief Carla Provost, U.S. Immigration and Customs Enforcement Executive Associate Director of Enforcement And Removal Operations Matthew Albence, Federal Health Coordinating Official for the 2018 UAC Reunification Effort Cmdr. Dr Jonathan White, Executive Office for Immigration Review Director James McHenry III, and U.S. Citizenship and Immigration Services Associate Director of Refugee, Asylum And International Operations Jennifer Higgins, are sworn in to testify as the Senate Judiciary Committee holds a hearing on the Trump administration's policies on immigration enforcement and family reunification efforts, on Capitol Hill in Washington, Tuesday, July 31, 2018. (AP Photo/J. Scott Applewhite)

FILE - In this April 5, 2018, file photo, California Secretary of State Alex Padilla speaks in Sacramento, Calif. Padilla is urging Californians to oppose the Trump administration plan for a citizenship question on the 2020 census. Padilla on Tuesday, July 31, 2018, launched an online portal for Californians to submit public comments through the federal registrar opposing the question. (AP Photo/Rich Pedroncelli, File)

LEGAL: Citizenship is asked on other countries’ census.

SPEAKING OUT: Massachusetts Attorney General Maura Healey, left, is among a group fighting a citizenship question on the Census, above.

WASHINGTON — State and local officials from Massachusetts and across the country urged the federal government to drop its plan to add a citizenship question to the 2020 U.S. Census, as Democrats and civil rights advocates rallied for public opposition to the plan.

The moves further crystallized immigration as the key issue both Republicans and Democrats are prioritizing ahead of November’s midterm elections.

In comments to the Census Bureau, which is mulling a regulation change to add the question to the census survey for the first time since 1950, Bay State Attorney General Maura Healey and other officials said the move would harm all residents in states like Massachusetts, resulting in underrepresentation in Congress and decreased federal funding.

The officials “represent areas with some of the largest minority and immigrant populations in the country.”

“Thus, we will be disproportionately affected by a census undercount, potentially reducing the number of congressional representatives and allocation of federal funding for infrastructure and public education, health, and housing for the next decade,” Healey and the other officials wrote in comments to the Commerce Department.

Yesterday was the last day comments could be submitted — spurring a flurry of messaging on social media and elsewhere by advocates pressing members of the public to chime in.

A Brookings Institution analysis estimated that inclusion of the question could deter 24.3 million people from participating in the census. That would include American citizens who fear that information they share could imperil family members who have green cards or are in the country illegally.

Civil rights advocates said those in minority communities and mixed-immigration households would be particularly hard hit.

Vanita Gupta, president and CEO of the Leadership Conference on Human Rights, said including the question for all census-takers is a method to disenfranchise people.

“Right now we are at a moment where the census is being politicized and weaponized for political gain,” Gupta said.

Commerce Secretary Wilbur Ross said in a memo earlier this year that the question was being added at the behest of the Department of Justice in an effort to better enforce the Voting Rights Act.

But documents released as part of an ongoing legal challenge Healey and other officials filed against the Commerce Department showed that anti-immigration hardliners lobbied for inclusion of the question, including Kansas Secretary of State Kris Kobach, who led President Trump’s short-lived commission on voter fraud.

In his memo, Ross noted that the question is already included in the supplemental American Community Survey, which is given to a limited sample of census-takers.